• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.291.2-291.2
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• 2016

3D semiconductor material of silicon that is used throughout the semiconductor industry currently faces a physical limitation of the development of semiconductor process technology. The research into the next generation of nano-semiconductor materials such as semiconductor properties superior to replace silicon in order to overcome the physical limitations, such as the 2-dimensional graphene material in 2D transition-metal dichalcogenide (TMD) has been researched. In particular, 2D TMD doping without severely damage of crystal structure is required different conventional methods such as ion implantation in 3D semiconductor device. Here, we study a p-type doping technique on tungsten diselenide (WSe2) for p-channel 2D transistors by adjusting the concentration of hydrochloric acid through Raman spectroscopy and electrical/optical measurements. Where the performance parameters of WSe2 - based electronic device can be properly designed or optimized. (on currents increasing and threshold voltage positive shift.) We expect that our p-doping method will make it possible to successfully integrate future layered semiconductor devices.

• Advances in materials Research
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• v.3 no.2
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• pp.117-128
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• 2014

Processable conducting polyaniline derivative with free amine functional groups was successfully synthesized from the monomer o-phenylenediamine in aqueous hydrochloric acid medium using ammonium persulfate as an oxidative initiator. The synthesized poly(o-phenylenediamine) (PoPD) in critical condition was found to be completely soluble in common organic solvents like dimethyl sulfoxide, N,N-dimethyl formamide etc. From the intrinsic viscosity measurement, the optimum condition for the polymerization was established. The polymer was characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy ($^1HNMR$) and thermogravimetric (TGA) analyses. The weight average molecular weights of the synthesized polymers were determined by the dynamic light scattering (DLS) method. From the spectroscopic analysis the structure was found to resemble that of polyaniline derivative with free amine functional groups attached to ortho/meta position in the phenyl ring. However, very little ladder unit was also present with in the polymer chain. The moderate thermal stability of the synthesized polymer could be found from the TGA analysis. The average DC conductivity of $2.8{\times}10^{-4}S/cm$ was observed for the synthesized polymer pellet after doping with hydrochloric acid.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.147-154
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• 1990

A sensitive method for the determination of total selenium in aerosol particles is described. The method involves dissolution of aerosol particles by $HNO_3-HClO_4$ mixed acids, pre-reduction of Se (VI) to Se (IV) by boiling hydrochloric acid, and hydride generation followed by atomic absorption detection. Dissolved Se (IV) in 4M hydrochloric acid is reacted with $NaBH_4$ to form $H_2Se$, which is subsequently collected in an U-tube cooled in liquid nitrogen. Upon the completion of $H_2Se$ generation, the collected $H_2Se$ is rapidly vaporized into a quartz cuvette burner by removing the U-tube from liquid nitrogen, atomized, and then detected by an atomic absorption spectrophotometer. The absolute sensitivity of the method is 0.49 ng/0.0044 Abs. The accuracy of the method evaluated by analyzing standard reference materials for urban aerosol is better than 10%. Analytical results for urban and rural aerosol particles are reported.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.236-237
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• 2001

In this study, experiments were carried out to measure the variations in the corrosion potential and current density of polarization curves with amorphous $Fe_{70}Cr_5Si_{10}B_{15}$ and $Co_{70}Cr_5Si_{10}B_{15}$ alloy ribbon. The results were particularly examined to identify the influences of corrosion potential including various conditions such as hydrochloric acid, temperature, salt, pH, and oxygen. The optimum conditions were established with variations including temperature, salt, pH, oxygen, corrosion rate, and resistance of corrosion potential. The mass tranfer coefficient(${\alpha}$) value was determined with the Tafel's slope for the anodic dissolution based on the polarization effect with optimum conditions. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity($I_{r}/I_{f}$).

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1035-1037
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• 1994

An ultrasensitive and selective stripping voltammetric scheme for the determination of rhodium is described. By the use of combined accumulation and catalytic effects in formaldehyde-hydrochloric acid medium, substantial improvement in the limit of detection can be obtained. Optimal experimental conditions were found to be 0.42 M hydrochloric acid solution containing 0.008${\%}$ formaldehyde, an accumulation potential of -0.70 V (vs. Ag/AgCl) and an accumulation time of 20 s. The stripping mode was differential pulse voltammetry. In these conditions the limit of detection lies at 2 ${\times}$ l0$^{-12}$ M (0.21 ppt). The relative standard deviation at 5 ${\times}$ l0$^{-11}$ M was 4.9${\%}$ (n=5). There were no serious interferences from other platinum group metal ions being the tolerable amounts more than 500 times that of rhodium.

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.227-232
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• 2008

Solvent extraction reaction of cobalt by Alamine336 from strong hydrochloric acid solution was identified by analyzing the solvent extraction data reported in the literature. Analysis of the data by graphical method revealed that Alamine336 took part in the solvent extraction reaction as a monomer in the concentration ranges, [Co(II)] : 0.0169 - 0.102 M, [Alamine336] ; 0.02- 1.75 M, and [HCl ] : 5 - 10 M. The following solvent extraction reaction and equilibrium constant was obtained from the experimental data by considering the activity coefficients of chemical species present in the aqueous phase. $Co^{2+}+2Cl^{-}+R_3NHCl_{org}=CoCl_3\;R_3NH_{org}$, $K_{ex}=2.21$ The distribution coefficients of cobalt predicted in this study agreed well with those reported in the literature.

• Membrane and Water Treatment
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• v.2 no.3
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• pp.187-205
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• 2011

The electric transport of the mixture of hydrochloric and phosphoric acids through strong base (Neosepta ACM) and weak base (Selemion AAV) anion-exchange membranes was investigated. The instantaneous efficiency of HCl removal from the cathode solution, $CE_{Cl}$, with and without $H_3PO_4$ was determined. It was found that $CE_{Cl}$ was 0.8-0.9 if the number of moles of elementary charge passed through the system, $n_F$, did not exceed ca. 80% of the initial number of HCl moles in the cathode solution, $n_{Cl,ca,0}$. The retention efficiency of $H_3PO_4$ in that range was close to one. The transport of acid mixtures was satisfactorily described by a model based on the extended Nernst-Planck and Donnan equations for $n_F$ not exceeding $n_{Cl,ca,0}$. Among the tested model parameters, most important were: concentration of fixed charges, the porosity-tortuosity coefficient, and the partition coefficient of an undissociated form of $H_3PO_4$. For the both membranes, the obtained optimal values of fixed charge concentration, $\bar{c}_m$, were up to 40% lower than the literature values of $\bar{c}_m$ obtained from the equilibrium measurements. Regarding the $H_3PO_4$ equilibria, it was sufficient to consider $H_3PO_4$ as a monoprotic acid.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.95-101
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• 1974

Studies on the optimum conditions of acid hydrolysis of sweet potato starch cake and its utilization on the production of Saccharomyces cerevisiae as a carbon source were conducted and the results showed as follows; 1.The highest hydrolysis rate, 62.7 ％ of the reducing sugar based on the weight of the dry matter, was obtained when the starch cake was hydrolyzed with 1.0％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 30 minutes. 2. But the yeast grew most favorably on the hydrolyzate obtained by treating the starch cake with 0.5％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 10 minutes. Reducing sugar content of hydrolyzate was 51.4％. 3. The optimum pH of the culture medium was 7.0, Cell growth reached to the maximum at 36 hours of cultivation time. 4. According to the vitamin requirement tests, Ca-pantothenate was found to be a promoting factor for the growth of the yeast cells. 5. "Gluten acid hydrolyzate" was most effective to the cell growth when added to the medium at the concentration of 0.1％ as a nitrogen source. 6. Sacch. cerevisiae could assimilate the sugars in the hydrolyzate about 89.1％, and the yields of the yeast cells showed 23.2mg/ml of culture medium.

• Journal of Sericultural and Entomological Science
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• v.18 no.1
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• pp.7-10
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• 1976

This experiments were carried out to know hatching power on treatments of cold temperature and hydrochioric acid Iron Late January to Early February. Used silkworm variety was Jam 103${\times}$ Jam 104 laying in Spring. The results may be summarized as follows: 1. The resting of silkworm eggs activated to Late January, to longer cold treatment was, the more effects of activating increased completely. So activated eggs were possible to incubation. 2. How to the light or short hours of hycrochloric acid were compare with heavy or long each other, it was inclined that the former seems to be worse than the latter. 3. On the interaction of cold treatments and hydrochloric acid, in case of short cold treatment, hatching power was better effect all treatments of hydrochloric acid than control, but no difference between specific gravity or treatment hours. On tile contrary, in case of more longer of cold treatments, hatching power depended not only upon the specific gravity, but also upon the treatment hours.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.672-681
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• 2015

As a part of abating the formaldehyde emission of amino resin-bonded wood-based composite panels, this study was conducted to investigate hydrolytic stability of urea-melamine-formaldehyde (UMF) resin depending on various hydrolysis conditions and hardener types. Commercial UMF resin was cured and ground into a powdered form, and then hydrolyzed with hydrochloric acid. After the acid hydrolysis, the concentration of liberated formaldehyde in the hydrolyzed solution and mass loss of the cured UMF resins were determined to compare their hydrolytic stability. The hydrolysis of cured UMF resin increased with an increase in the acid concentration, time, and temperature and with a decrease in the smaller particle size. An optimum hydrolysis condition for the cured UMF resins was determined as $50^{\circ}C$, 90 minutes, 1.0 M hydrochloric acid and $250{\mu}m$ particle size. Hydrolysis of the UMF resin cured with different hardener types showed different degrees of the hydrolytic stability of cured UMF resins with a descending order of aluminum sulfate, ammonium chloride, and ammonium sulfate. The hydrolytic stability also decreased as the addition level of ammonium chloride increased. These results indicated that hardener types and level also had an impact on the hydrolytic stability of cured UMF resins.